Removable cartridge for liquid diffusion device

ABSTRACT

A removable cartridge for use with a liquid diffusion device is provided. The removable cartridge includes a cartridge housing defining an internal housing cavity, partially filled with a liquid to be diffused, and a diffusion head positioned within the internal housing cavity with a venturi device for generating diffused liquid from the liquid contained in the internal housing cavity. The diffusion head defines at least a portion of a gas supply conduit that extends from a bottom end of the removable cartridge to the venturi device through the liquid to be diffused to enable the venturi device to be supplied with pressurized gas from an external source via the bottom end of the removable cartridge.

BACKGROUND Technical Field

The present disclosure relates generally to liquid diffusion devicesand, more specifically, to a removable cartridge for use with a liquiddiffusion device where the liquid to be diffused is contained within thecartridge.

Description of the Related Art

Diffusion devices in the past have had the ability to dispense scent orother liquids throughout the atmosphere of desired spaces but havesuffered from several drawbacks. Changing the scent or product that isbeing diffused has typically required that a reservoir of the diffusingdevice be emptied and then filled with the new liquid or scent.Conventional reservoirs may be configured to be refilled directly withthe liquid to be diffused, which can be messy or have a highlyconcentrated odor. This refilling may not be desirably carried out in apublic setting, such as a store, restaurant, casino or other commercialsetting where the scent or other product may be diffused. Additionally,having to deal with bulk refills that must be poured or otherwise placedinto the reservoir of the diffusion device may not be a desirablearrangement for home or non-commercial diffusion devices. An improvedability to refill or recharge a diffusion device with scent or otherproduct is desirable.

Some diffusion devices have been developed to address the aforementionedissues by enabling a cartridge containing the liquid to be diffused tobe removed from a host device upon depletion of the liquid and replacedwith another like cartridge. Such diffusion devices and removablecartridges thereof, however, may be overly complex, costly and/or sufferfrom other deficiencies or drawbacks, such as, for example, dischargingdiffused liquid with less than ideal characteristics, or the cartridgesbeing susceptible to leakage, tampering, fouling and/or contamination.Accordingly, Applicant believes that improved cartridges and cartridgecomponents for liquid diffusion devices are desirable.

BRIEF SUMMARY

The removable cartridges for use with liquid diffusion devices andcomponents thereof shown and described herein provide removablecartridges and cartridge components with efficient form factors that areparticularly effective at treating spaces with diffused liquid havingextremely small liquid particles.

At least one embodiment of a removable cartridge for use with a liquiddiffusion device may be summarized as including a cartridge housingdefining an internal housing cavity partially filled with a liquid to bediffused and a diffusion head positioned within the internal housingcavity, which includes a venturi device for generating diffused liquidfrom the liquid contained in the internal housing cavity. The diffusionhead defines at least a portion of a gas supply conduit that extendsfrom a bottom end of the removable cartridge to the venturi devicethrough the liquid to be diffused to enable the venturi device to besupplied with pressurized gas from an external source via the bottom endof the removable cartridge.

The cartridge housing may include a plurality of housing pieces fixedlycoupled together to prevent non-destructive disassembly of the removablecartridge and may be configured to be discarded as a unit upon depletionof the liquid. A lower end of the diffusion head may be fixedly coupledto the cartridge housing in a liquid tight manner to prevent leakagefrom the bottom end of the removable cartridge.

The removable cartridge may further include an insert positioned aboveof the diffusion head, which has an inlet to receive diffused liquidgenerated by the venturi device, an outlet zone from which to dischargethe diffused liquid toward an external environment, and a tortuouspassage extending between the inlet and the outlet zone. The tortuouspassage may be configured to aid in further reducing an average particlesize of the diffused liquid as the diffused liquid moves through thetortuous passage. Additionally, the tortuous passage may be configuredto provide a convoluted flow path that retards a flow of the liquid tobe diffused through the insert when the removable cartridge istemporarily held upside-down. An initial fill level of the liquid to bediffused may be below the venturi device when the removable cartridge isupright and below a central axis of the cartridge housing when theremovable cartridge is upended and rests sideways, and the tortuouspassage may be configured to provide a convoluted flow path thatincludes a portion above the central axis when the removable cartridgeis upended and rests sideways to prevent the liquid to be diffused fromtraversing the entirety of the tortuous passage.

A lower portion of the insert may include an indentation having animpact surface to be impinged upon by the diffused liquid generated bythe venturi device during operation of the liquid diffusion device. Theinsert may be sandwiched between the cartridge housing and the diffusionhead. The cartridge housing may include a lower housing portion and anupper housing portion, and the diffusion head and the insert may extendlongitudinally between the lower housing portion and the upper housingportion.

An upper portion of the diffusion head and a lower portion of the insertmay define a primary expansion chamber immediately above the venturidevice. The primary expansion chamber may be in fluid communication withthe internal housing cavity external of the diffusion head via aplurality of apertures provided in the upper portion of the diffusionhead. The upper portion of the diffusion head may define a bulkhead thatimpedes the diffused liquid generated by the venturi device from exitingthe primary expansion chamber other than through the plurality ofapertures. An upper end of the diffusion head and the insert may besized and shaped to nest together.

In one embodiment, the removable cartridge may consist of the cartridgehousing, the diffusion head, the insert, the liquid to be diffused and aconduit that extends from a side of the venturi device of the diffusionhead to a lower region of the internal housing cavity to enable theliquid contained therein to be drawn into a path of the pressurized gasas it moves through the venturi device during operation.

The removable cartridge may include a plurality of chambers downstreamof the venturi device through which the diffused liquid sequentiallymoves towards an outlet of the removable cartridge. The plurality ofchambers may include a primary expansion chamber, a secondary chamberand a tertiary chamber. The primary expansion chamber may be locatedimmediately above the venturi device and may be bounded at least in partby a concave impact structure located opposite the venturi device. Thesecondary chamber may be provided above a fluid level of the liquid tobe diffused and may be separated from the primary expansion chamber by abulkhead having a plurality of apertures that provide fluidcommunication between the primary expansion chamber and the secondarychamber. The tertiary chamber may include a tortuous passage leadingfrom the secondary chamber toward the outlet of the removable cartridge.

Another embodiment of a removable cartridge for use with a liquiddiffusion device may be summarized be summarized as including acartridge housing including a lower housing portion and an upper housingportion that are fixedly coupled together to prevent non-destructivedisassembly of the cartridge and which collectively define an internalhousing cavity that is partially filled with a liquid to be diffused,and a diffusion head retained within the internal housing cavity, whichincludes a venturi device for generating a diffused liquid stream. Alower portion of the diffusion head may define a gas supply conduit thatextends from a bottom end of the cartridge to the venturi device toenable the venturi device to be supplied with pressurized gas from anexternal source via the bottom end.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

FIG. 1 is an isometric view of a removable cartridge for a liquiddiffusion device, according to one embodiment.

FIG. 2 is an isometric partial cross-sectional view of the removablecartridge of FIG. 1 showing internal components thereof.

FIG. 3 is a cross-sectional view of the removable cartridge of FIG. 1taken along line 3-3 of FIG. 2.

FIG. 4 is a cross-sectional view of the removable cartridge of FIG. 1taken along line 4-4 of FIG. 2.

FIG. 5 is an isometric partial cross-sectional view of a diffusion headand an insert of the removable cartridge of FIG. 1.

FIG. 6 is a cross-sectional view of the insert of the removablecartridge of FIG. 1 taken along line 6-6 of FIG. 4 showing a flow pathfor diffused liquid moving therethrough.

FIG. 7 is a cross-sectional view of the removable cartridge of FIG. 1taken along line 4-4 of FIG. 2, but rotated on its side.

FIG. 8 is an isometric partial cross-sectional view of a removablecartridge for a liquid diffusion device, according to anotherembodiment.

FIG. 9 is an isometric view of an insert of the removable cartridge ofFIG. 8.

FIG. 10 is a cross-sectional view of the insert shown in FIG. 9 showinga flow path for diffused liquid moving therethrough.

DETAILED DESCRIPTION

In the following description, certain specific details are set forth inorder to provide a thorough understanding of various disclosedembodiments. However, one skilled in the relevant art will recognizethat embodiments may be practiced without one or more of these specificdetails. In other instances, well-known devices, structures andtechniques associated with liquid diffusion devices, components thereofand related methods of diffusing liquid may not be shown or described indetail to avoid unnecessarily obscuring descriptions of the embodiments.For example, embodiments of the removable cartridges and cartridgecomponents (e.g., cartridge inserts) disclosed herein may be used in awide variety of host diffusion devices, including those with an onboardpressurized gas source (e.g., an air compressor or pump) and a controlsystem for discharging diffused liquid in regular or irregular dutycycles or as otherwise desired. Such diffusion devices, which may beadapted to receive embodiments of the cartridges and cartridgecomponents described herein are not shown or described in further detailto avoid unnecessarily obscuring descriptions of such embodiments.Examples of diffusion devices and aspects and related methods thereofwhich may be used in combination with the cartridge and cartridgecomponents described herein are shown in U.S. Pat. Nos. 7,712,683,7,930,068 and 8,855,827, all of which are incorporated herein byreference in their entirety.

Unless the context requires otherwise, throughout the specification andclaims which follow, the word “comprise” and variations thereof, suchas, “comprises” and “comprising” are to be construed in an open,inclusive sense, that is as “including, but not limited to.”

Reference throughout this specification to “one embodiment” or “anembodiment” means that a particular feature, structure or characteristicdescribed in connection with the embodiment is included in at least oneembodiment. Thus, the appearances of the phrases “in one embodiment” or“in an embodiment” in various places throughout this specification arenot necessarily all referring to the same embodiment. Furthermore, theparticular features, structures, or characteristics may be combined inany suitable manner in one or more embodiments.

As used in this specification and the appended claims, the singularforms “a,” “an,” and “the” include plural referents unless the contentclearly dictates otherwise. It should also be noted that the term “or”is generally employed in its sense including “and/or” unless the contentclearly dictates otherwise.

The present disclosure relates generally to liquid diffusion devices andmore specifically to a removable cartridge 100, 200 for use with adiffusion device where the liquid to be diffused is contained within thecartridge 100, 200, and to components thereof and related methods ofdischarging diffused liquid into a space. The cartridges 100, 200described herein may be used with a diffusion device or system having aunit or housing adapted to removably receive the cartridges 100, 200such that the diffusion device or system can be recharged with liquid tobe diffused. In some instances, a diffusion device may be provided whichincludes such a unit or housing, a removable liquid cartridge 100, 200and a cover enclosing both the unit or housing and the cartridge 100,200, similar to the example diffusion devices shown and described inU.S. Pat. No. 7,712,683, assigned to Prolitec, Inc., which isincorporated herein by reference in its entirety. One or moreoperational controls or status indicators may be provided for operatingthe device and an outlet or opening may be provided in the device topermit a diffused liquid generated from the liquid within the cartridge100, 200 to be discharged into the environment about the device. Whenreceived in a host diffusion device, the removable cartridge 100, 200engages or is otherwise coupled to an outlet of a source of pressurizedgas to enable the pressurized gas to be selectively passed through thecartridge 100, 200 as described herein to diffuse the liquid containedtherein. The gas used to drive the diffusion of the liquid may be any ofa variety of inert gases. In some instances, the diffusion device mayinclude an air compressor utilizing normal room air to drive thediffusion. However, other gases such as but not limited to nitrogen,carbon dioxide, or other similar atmospheric gases might be used. It mayalso be desirable to use a gas that reacts with the liquid to bediffused, such as but not limited to oxygen and other non-inert gases.Also, the diffusion device might utilize, for example, but be notlimited to, an onboard compressor, an onboard source of compressed gassuch as a pressurized reservoir, or connection to an external source ofcompressed gas.

Within the present disclosure, the terms atomize and diffuse are used intheir various forms interchangeably. They are intended to refer togenerally the same action, that being the dispersion of liquid into verysmall particle sizes (preferably but not limited to one micron or lessin size) and releasing the particles into the atmosphere of a generallyenclosed space. Discharging diffused liquid with particularly smallparticles helps ensure that the liquid to be dispersed remains airbornelong enough to effectively treat the space.

One approach to providing small particle sizes is to incorporate adispersion or gas-liquid mixing location adjacent an expansion chamber.The mixed gas and liquid combination may contain particles of greaterthan desirable size. Allowing this mix to remain resident within theexpansion chamber prior to release into the treated space will allowlarger particles to precipitate out of the mix. Structures that a flowof the gas and liquid mix impinge upon may also assist in the collectionof these larger particles and leave only the desired predominantlysmaller sized particle to be released. The expansion chamber may bemaintained at a positive pressure with respect to the atmosphericpressure within the space to be treated, so that the gas and liquid mixwill be injected from the device into the space. Alternatively, theexpansion chamber may generally be maintained at the atmosphericpressure of the space to be treated with the flow of gas through thechamber providing the impetus for movement of the gas and liquid mixfrom the device into the space to be treated. It may also be possible tohave the pressure within the expansion chamber at a pressure lower thanthat of the treated space, which may aid in the mixing or dispersion ofthe diffused liquid within the atmosphere within the space.

Within the context of this disclosure, diffusion also generally refersto a process or method of dispersing a liquid without destroying theintegrity of the liquid compound. While some degree of reactivitybetween the gas and the liquid may be desirable, diffusion generallydoes not change the nature of the liquid, unlike heating or theapplication of electrical energy into the liquid to diffuse the liquid.

The removable cartridges 100, 200 and components thereof describedherein may be used with a diffusion device to provide or introduce apleasant or soothing scent (or some other type of liquid that may beused as an airborne treatment or compound) into the air space of a roomor other enclosed space. The particular liquid to be dispensed by thediffusion device is contained within the removable cartridge 100, 200.Other possible types of liquids that may be dispersed may includedecontamination agents, insecticides, insect repellents, and manydifferent types of liquids that may be desirably dispersed within anenclosed space. The present disclosure is not limited to a particulartype or nature of liquid to be dispersed, but is intended to encompassany desirable airborne liquid treatments that are preferably dispersedwithin an enclosed space to be effective. The term enclosed space, asused herein, refers to any volume of space within which the atmosphericturnover is sufficiently slow to permit the dispersed liquid to have itsdesired effect within the space. Larger spaces, such as concert halls,casinos, lobbies, etc., may have one or more openings into the space andstill have the desired characteristics to permit treatment with adiffused liquid. Other spaces may be preferably fully enclosed to permittreatment by the selected liquid. In other cases, the liquid used fortreatment may preferably be used in a sealed space for maximumeffectiveness or for safety reasons. Within the scope of the presentdisclosure, it is not intended to limit the nature, size orconfiguration of the space to be treated except as may be appropriatefor the liquid used to treat the space and the nature of treatmentdesired within the space.

A source of pressurized gas 102, 202 (FIGS. 2 and 8) may be providedwithin or in connection with the diffusion device that receives theremovable cartridges 100, 200. The source of pressurized gas 102, 202may comprise, for example, a small air compressor or pump, an internalreservoir, or a connection to an external source of pressurized gas. Insome embodiments, controls may be configured to permit adjustment of thetiming and/or pressure level of the pressurized gas or air generated bythe pump or compressor that is ultimately directed into and passesthrough the cartridge 100, 200. In some instances, the operatingpressure may be relatively low, such as, for example, less than about 2psi gauge pressure or about 1.5 psi gauge pressure. Within the cartridge100, 200, the pressurized gas is directed to atomize the liquidcontained therein and to aid in the dispersion of the atomized liquidinto the air space to be treated.

In some instances, it may be desirable to have an indirect route fromthe point of actual atomization of the liquid and an outlet 114, 214(FIGS. 1 through 4 and 8) through which a portion of the atomizedparticles exit from the cartridge 100, 200. As will be described ingreater detail below, embodiments of the removable cartridges 100, 200described herein provide an atomization zone where liquid from thecartridge 100, 200 and pressurized gas meet and are mixed. In addition,the cartridges 100, 200 may also provide an expansion chamber orchambers within the cartridge 100, 200 where the atomized liquid isretained until a portion of the atomized liquid is allowed to exit thecartridge 100, 200 and host diffusion device. As described in greaterdetail elsewhere, the cartridges 100, 200 may combine storage of theliquid to be diffused, an atomization structure to transform the liquidinto an airborne concentration, an expansion chamber or chambers, and atortuous path or passage towards the outlet 114, 214 of the cartridge100, 200. Cartridges 100, 200 according to the present disclosure mayalso be used in conjunction with one or more external expansion chambersto further aid in the separation of particle sizes and permit onlydesirably small particles to be allowed into the space to be treated.

Referring now to FIGS. 1 through 7, one example embodiment of aremovable cartridge 100 is shown for use with a diffusion device whichis configured to treat a space with diffused liquid generated by a flowof pressurized gas moving through the cartridge 100. As shown in FIG. 1,the removable cartridge 100 may include a housing 110 having two or moreportions or pieces 110 a, 110 b coupled together to define a fluidreceptacle having an internal cavity 113, which is partially filled withliquid 111 to be diffused. In some instances, the housing portions orpieces 110 a, 110 b may be fixedly coupled together to preventnon-destructive disassembly of the removable cartridge 100, making iteffectively tamperproof. This may be desirable to prevent users fromrefilling and reusing a spent cartridge that may be ineffective or lesseffective in treating the space due to fouling or build-up of residuewithin the cartridge 100 from prior use. As an example, and withreference to FIGS. 2 through 4, the housing portion or pieces 110 a, 110b, may be provided with interlocking structures 120 that snap orotherwise couple together in a manner that prevents non-destructivedisassembly of the housing 110, and hence cartridge 100. A seal 122,such as an o-ring seal or other sealing device, may be provided betweenthe housing portions or pieces 110 a, 110 b near the interlockingstructures 120 to provide a liquid tight seal when the housing 110 isassembled. In this manner, the liquid 111 to be diffused may beprevented from leaking from the housing 110 at an interface between thehousing portions or pieces 110 a, 110 b. Upon depletion of the liquid111, the cartridge 100 may be readily removed and replaced with a likecartridge 100 for continued treatment of the environment surrounding thediffusion device, and the depleted cartridge 100 may be discarded as anintact unit or collected for refurbishment purposes.

With reference to FIG. 1, the housing 110 of the cartridge 100 mayinclude an upper housing portion 110 a and a lower housing portion 110 bfixedly coupled together. A cartridge inlet 112 may be provided at abottom end of the lower housing portion 110 b to receive a flow ofpressurized gas during operation and a cartridge outlet 114 may beprovided in the upper housing portion 110 a for discharging diffusedliquid generated by the cartridge 100 during operation. The cartridgeinlet 112 and the cartridge outlet 114 may be aligned along a centralaxis A defined by the housing 110. The housing 110 may be rotationallysymmetric about the central axis A. For example, as shown in FIG. 1, thehousing 110 may resemble an urn or similar receptacle that isrotationally symmetric about the central axis A. In other instances, thehousing 110 may be asymmetrically shaped and the cartridge inlet 112 andcartridge outlet 114 may not be aligned vertically along a common axis.Respective caps or plugs 104, 106 may be provided to temporarily closethe cartridge inlet 112 and cartridge outlet 114 during storage,transport or the like to prevent fouling or contamination of thecartridge 100 or possible leakage of the liquid 111 retained therein.

Internal components and structures of the cartridge 100 and relatedfunctionality will now be described with reference to FIGS. 2 through 4.According to the illustrated embodiment of the cartridge 100, theinternal components and structures provide, among other things, a flowpath through the cartridge 100 from the cartridge inlet 112 to thecartridge outlet 114, as represented by the arrows labeled 130 a-130 h.When installed in a host diffusion device, the cartridge inlet 112 iscoupled a source of pressurized gas 102 such that the gas may beperiodically forced through the cartridge 100 as generally representedby the arrows labeled 130 a-130 h to combine with the liquid 111 and toexit as a gas-liquid mixture comprising particularly small liquidparticles carried by the gas, referred to generally herein as a diffusedliquid.

As shown in FIGS. 2 through 4, the pressurized gas enters the cartridge100 through the cartridge inlet 112 at a bottom end of the housing 110and then flows through a diffusion head 140 provided within the housing110, which includes a venturi device 142 for drawing the retained liquid111 into the moving gas stream, and a cartridge insert 170 beforeexiting the cartridge 100 through the cartridge outlet 114. Moreparticularly, the pressurized gas enters the cartridge 100 through thecartridge inlet 112 at a bottom end of the housing 110, as representedby the arrow label 130 a, and then flows upwardly through a gas supplyconduit 152 defined by an interior surface 154 of a lower portion 144 ofthe diffusion head 140, as represented by the arrow labeled 130 b. Thegas then flows through the venturi device 142 drawing in liquid 111 froma fluid reservoir surrounding the lower portion 144 of the diffusionhead 140 within the internal housing cavity 113 of the housing 110 tocreate a gas-liquid mixture comprising atomized liquid (also referred toherein as diffused liquid) that is discharged into an expansion chamber148 provided by an upper portion 146 of the diffusion head 140, asrepresented by the arrow labeled 130 c. The diffused liquid is thendirected toward an impact structure or surface 182 located opposite theventuri device 142 wherein at least some of the diffused liquid impactsand collects on the impact structure or surface 182 and is routed backto any remaining fluid 111 in the fluid reservoir to be reintroducedinto the gas stream by the venturi device 142. At least some other ofthe diffused liquid is redirected to flow down around bulkhead portions156 of the diffusion head 140 and to pass through passageways 158 in thediffusion head 140 leading to a portion of the internal cavity 113 ofthe housing above the fluid level L of liquid 111 in the cartridge 100,as represented by the arrows labeled 130 d and 130 e. From there, someof the diffused liquid may collect on the exposed interior surfaces ofthe housing 110 or other internal structures of the cartridge 100, orotherwise precipitate out of the gas and atomized liquid, and rejoin theliquid 111 in the fluid reservoir to be reintroduced into the gas streamby the venturi device 142. Some other of the diffused liquid may bepropelled into the cartridge insert 170 via an inlet 172 thereof, asrepresented by the arrow labeled 130 f. From the inlet 172 of the insert170, the diffused liquid proceeds along a tortuous passage through thecartridge insert 170, as represented by the arrows labeled 130 g, beforepassing through an outlet passageway 115 in the housing 110 that leadsto the cartridge outlet 114 to be discharged from the cartridge 100, asrepresented by the arrow labeled 130 h. In making this convolutedjourney from the expansion chamber 148 to the cartridge outlet 114, theliquid particle size distribution of the diffused liquid is refined suchthat only particularly fine particles are successfully discharged fromthe cartridge 100 with relatively larger particles collecting on one ormore surfaces of the internal structures and components of the cartridge100, or otherwise precipitating out of the gas, for rejoinder withremaining liquid 111 in the liquid reservoir for reintroduction into thegas stream passing through the venturi device 142.

Further details of the diffusion head 140 and cartridge insert 170 willnow be discussed with reference to FIG. 5. As shown in FIG. 5, thediffusion head 140 may include a unitary diffusion head body 141including an upstream or lower portion 144 and a downstream or upperportion 146. For example, in some instances the diffusion head 140 maybe molded or otherwise formed as a unitary piece of material, such as asuitable plastic or polymeric material. The lower portion 144 of thediffusion head 140 may be sized and shaped to nest closely with acorresponding portion of the housing 110, as shown in FIGS. 1 through 4,or to otherwise interface with the housing 110, and may be fixedlyjoined to the housing 110 via spin welding, ultrasonic welding otherjoining processes to create a liquid-tight seal between the housing 110and the lower portion 144 of the diffusion head 140. In some instances,such as the example embodiment of the diffusion head 140 shown in FIG.5, the lower portion 144 of the diffusion head body 141 may include aflange 143 or other feature, such as a step, projection, tab, indent, orgroove, that interfaces with the housing 110 to assist in fitment andjoining of the components.

With continued reference to FIG. 5, the lower portion 144 of thediffusion head body 141 includes an interior surface 154 that definesthe gas supply conduit 152 that leads from the cartridge inlet 112 at abottom end of the cartridge 100 toward the venturi device 142. The gassupply conduit 152 may also be partially defined by a divider portion145 of the diffusion head body 141 which divides the upper portion 146of the diffusion head 140 from the lower portion 144. The dividerportion 145 separates and isolates the gas supply conduit 152 from theexpansion chamber 148 with the exception of a flow passage 147 throughthe venturi device 142 which may provide the only fluid communicationbetween the gas supply conduit 152 and the expansion chamber 148.

With reference to FIGS. 2 and 3, the liquid 111 to be diffused maysurround the lower portion 144 of the diffusion head 140 such that gasenters the cartridge 100 from a bottom 118 of the cartridge 100 andpasses through a region of the diffusion head 140 surrounded by theliquid 111 before reaching the venturi device 142. At the venturi device142, the gas is accelerated via the flow passage 147 and a lowerpressure zone is created which draws the liquid 111 to be diffusedthrough a suction tube 119 that provides fluid communication between theliquid reservoir that surrounds the lower portion 144 of the diffusionhead 140 and the venturi device 142. The initial volume of liquid 111supplied with the cartridge 100 preferably does not fill the entireinterior cavity 113 of the housing 110, but rather defines a fluid levelL that is below the venturi device 142.

As shown in FIG. 5, the diffusion head 140 may include a tube receivingpassage 149 in the divider portion 145 of the diffusion head body 141 toreceive one end of the suction tube 119 and to position an outlet of thesuction tube 119 in fluid communication with the flow passage 147 of theventuri device 142 such that the liquid 111 may be drawn into the pathof the pressurized gas as it is accelerated via the flow passage 147 ofthe venturi device 142. The flow passage 147 of the venturi device 142may comprise a convergent entrance, a narrow throat, a side port forintroduction of the liquid, and a divergent outlet which are configuredto accelerate the flow of gas, draw in the liquid 111 through the sideport and discharge diffused liquid into the downstream expansion chamber148 provided by the upper portion 146 of the diffuser head 140. The sizeand shape of the flow passage 147 may be configured based oncharacteristics of the gas flow, the geometry of the gas supply conduit152 and the volume and velocity of gas required to effectively drawliquid 111 up the suction tube 119 and atomize liquid 111 in the venturidevice 142.

With continued reference to FIG. 5, the diffused liquid may bedischarged from the venturi device 142 with sufficient force to cause atleast some of the atomized liquid particles suspended in the gas,particularly the relatively larger particles, to impinge upon andcollect on the underside of the cartridge insert 170, which is providedopposite the venturi device 142 to serve as an impact structure,preferably a concave impact structure. More particularly, the insert 170may include a lower portion having an indentation or depression 180 thatincludes an impact surface 182 to be impinged upon by the diffusedliquid generated by the venturi device 142 during operation. In someinstances, the impact surface 182 may be concave and may diverge in adownward direction to direct liquid condensed or collected thereonradially outward and downward. In some embodiments, the impact surface182 may be a conical or frustoconical surface. Liquid collecting on theunderside of the insert 170 may drip or run down onto the dividerportion 145 of the diffusion head 140 and drain to the liquid reservoirvia the passageways 158 provided in the upper portion 146 of thediffusion head 140, which in some embodiments may provide the only fluidcommunication between the expansion chamber 148 and the internal cavity113 of the housing 110 external of the diffusion head 140.

As shown in FIG. 5, the insert 170 is positioned above of the diffusionhead 140 and includes a body 171, an inlet 172 provided in the body 171to receive the diffused liquid generated within the cartridge 100 duringoperation of the liquid diffusion device, an outlet zone 174 defined atleast in part by the body 171 through which to discharge the diffusedliquid toward the external environment, and a tortuous passage 176extending between the inlet 172 and the outlet zone 174 to aid infurther reducing an average liquid particle size of the diffused liquidas the diffused liquid moves through the tortuous passage 176 duringoperation. The inlet 172 may be located at a periphery 173 of the body171, the outlet zone 174 may be located at a central region 175 of thebody 171, and the tortuous passage 176 may spiral or otherwise extend ina convoluted manner between the inlet 172 and the outlet zone 174. Thetortuous passage 176 may be at least partially defined by a verticalsidewall 178 of the body 171. The sidewall 178 may extend from theperiphery 173 of the body 171 into the central region 175 of the body171. A floor 179 of the insert 170 may be inclined or sloped toward theinlet 172 to assist in rerouting liquid that has precipitated out of thegas/diffused liquid mixture or that has otherwise collected on surfacesof the insert 170 as the mixture passes through the tortuous passage 176during operation back to rejoin any remaining liquid 111 in the internalcavity 113 surrounding the lower portion 144 of the diffusion head 140to be reintroduced into the gas stream passing through the venturidevice 142.

As shown in FIG. 5, the tortuous passage 176 may be open in an upwarddirection and may be at least partially capped with a correspondingportion 117 of the housing 110 when the cartridge 100 is assembled todefine an aerosol outlet at a remaining uncovered portion at the outletzone 174. The insert 170 may also include a chamfer 177 of other featureor structure for interfacing with the housing 110 to assist in alignmentand fitment of the insert 170 within the cartridge 100 as the insert 170is sandwiched between the cartridge housing 110 and the diffusion head140 in the assembled condition. In the assembled condition, thediffusion head 140 and the insert 170 extend longitudinally between thelower housing portion 110 b and the upper housing portion 110 a todefine a central core of the cartridge 100 that fully traverses thehousing 110 in a longitudinal direction.

The body 171 of the insert 170 is preferably formed as a single, unitarypiece that includes the tortuous passage 176 and is coupled to orotherwise positioned adjacent the upper portion 146 of the diffusionhead 140 to cap the expansion chamber 148. For example, in someinstances the insert 170 may be molded or otherwise formed as a unitarypiece of material, such as a suitable plastic or polymeric material. Theupper portion 146 of the diffusion head 140 and the insert 170 may besized and shaped to nest together. For example, the upper portion 146 ofthe diffusion head 140 may include a recess or shelf 150 to receive andsupport the insert 170. In some embodiments, the insert 170 may befixedly joined to the diffusion head 140 via spin welding, ultrasonicwelding or other joining techniques. Still further, although thediffusion head 140 and the insert 170 are described herein as twoseparate components positioned or joined together, it is appreciatedthat the structures and features of these components may be formed as asingle unitary piece via an additive manufacturing process, for example.In other instances, the structures and features of the diffusion head140 and the insert 170 may be provided by more than two pieces that arejoined or otherwise coupled together. In the particularly advantageousembodiment illustrated in FIGS. 1 through 7, however, the removablecartridge 100 consists, or consists essentially, of the cartridgehousing 110, the diffusion head 140, the cartridge insert 170, theliquid 111 to be diffused, and the conduit or tube 119 that extends froma side of the venturi device 142 of the diffusion head 140 to a lowerregion of the internal housing cavity 113 to enable the liquid 111contained therein to be drawn into the path of the pressurized gas as itmoves through the venturi device 142 during operation.

According to the illustrated embodiment, the tortuous passage 176 ishelical and makes at least one full revolution about the central axis A.It is appreciated, however, that the tortuous passage 176 may take on avariety of different forms. For example, the tortuous passage 176 mayinclude a curvilinear path that at least partially encircles the centralaxis A as it moves from the inlet 172 toward the outlet zone 174. Inother instances, the tortuous passage 176 may include a path with aplurality of straight segments angled relative to each other to providea number of turns. In still other instances, the tortuous passage 176may include a path that combines linear and non-linear path segments.The cross-sectional shape of the tortuous passage 176 may also varyalong the tortuous passage 176. For example, a cross-sectional profileof at least a portion of the tortuous passage 176 may narrow in adownstream direction, that is in a direction from the inlet 172 towardthe outlet zone 174. This narrowing of the tortuous passage 176 mayfurther assist in refining the composition of the diffused liquid toinclude only the finest of liquid particles.

Irrespective of particular configuration, the tortuous passage 176follows a non-linear path that, among other things, assists inpreventing liquid 111 from leaking from the cartridge 100 when thecartridge 100 is upended. For example, if the cartridge 100 istemporarily held upside down, the tortuous passage 176 will assist inslowing the progression of liquid 111 within the cartridge 100 towardthe outlet zone 174 and hence the outlet 114 of the cartridge 100. Inthis manner, the cartridge 100 can be subsequently righted without theloss of fluid. Moreover, in the event the cartridge 100 is upended andcomes to rest on its side, the cartridge 100 is configured such that thevolume of liquid 111 supplied with the cartridge 100 will not rise abovethe central axis A of the cartridge 100, as illustrated in FIG. 7. Inthis manner, the tortuous passage 176 will prevent the liquid 111 fromspilling out of the outlet 114 as the liquid 111 will be unable to movethrough the entirety of the tortuous passage 176 as at least a portionof the tortuous passage 176 will be located above the fluid level L₂ ofthe liquid 111.

With reference again to FIGS. 2 through 4, it will be appreciated thatthe housing 110 and internal components of the cartridge 100 define aplurality of distinct chambers downstream of the venturi device 142through which the diffused liquid sequentially travels before beingdischarged from the cartridge 100 and ultimately into a surroundingenvironment. More particularly, the upper portion 146 of the diffusionhead 140 and a lower portion of the insert 170 define a primaryexpansion chamber 148 immediately above the venturi device 142, asecondary chamber is provided external of the diffusion head 140 and theinsert 170 within internal cavity 113 of the housing 110 above the fluidlevel L of the liquid 111 to be diffused, and a tertiary chamber isprovided by the tortuous passage 176 of the insert 170. Passageways orapertures 158 in the upper portion 146 of the diffusion head 140 providefluid communication between the primary expansion chamber 148 and thesecondary chamber. The upper portion 146 of the diffusion head 140 alsodefines a bulkhead or bulkhead portions 156 that impede the diffusedliquid generated by the venturi device 142 from exiting the primaryexpansion chamber 148 other than through the plurality of passageways orapertures 158. The inlet 172 of the insert 170 provides fluidcommunication between the secondary chamber and the tertiary chamber(i.e., the tortuous passage 176). Although only one inlet 172 and onetortuous passage 176 is shown providing the sole passage for thediffused liquid to exit the cartridge 100, it is appreciated that aplurality of inlets 172 may be provide to enable diffused liquid toenter one or more tortuous passages leading to the outlet 114 of thecartridge 100. The distinct chambers described above (i.e., the primaryexpansion chamber, the secondary chamber and the tertiary chamber)collectively assist in refining the composition of the diffused liquidto include only the finest liquid particles as the diffused liquid movessequentially through the chambers during operation. For instance, by thetime the gas/diffused liquid mixture exits from cartridge 100, there hasbeen some residence time in each of the distinct chambers to permitundesirably large liquid particles or droplets to precipitate out of orotherwise separate from the mixture and be returned to the liquidreservoir within the internal cavity 113 of the housing 110 external ofthe diffusion head 140 for later atomization and dispersion. In thismanner, the removable cartridge 100 and components thereof may provide acartridge solution for a diffusion device which has an efficient formfactor that is particularly effective at treating spaces with diffusedliquid having extremely small liquid particles.

Referring now to FIGS. 8 through 10, another example embodiment of aremovable cartridge 200 is shown for use with a diffusion device whichis configured to treat a space with diffused liquid generated by a flowof pressurized gas moving through the cartridge 200. As shown in FIG. 8,the removable cartridge 200 may include a housing 210 having two or moreportions or pieces 210 a, 210 b coupled together to define, among otherthings, a fluid receptacle having an internal cavity 213 partiallyfilled with liquid 211 to be diffused. In some instances, the housingportions or pieces 210 a, 210 b may be fixedly coupled together toprevent non-destructive disassembly of the removable cartridge 200,making it effectively tamperproof. This may be desirable to preventusers from refilling and reusing a spent cartridge that may beineffective or less effective in treating the space due to fouling orbuild-up of residue within the cartridge 200 from prior use. As anexample, and with reference to FIG. 8, the housing portion or pieces 210a, 210 b, may be provided with interlocking structures 220 that snap orotherwise couple together in a manner that prevents non-destructivedisassembly of the housing 210, and hence cartridge 200. A seal 222,such as an o-ring seal or other sealing device, may be provided betweenthe housing portions or pieces 210 a, 210 b near the interlockingstructures 220 to provide a liquid tight seal when the housing 210 isassembled. In this manner, the liquid 211 to be diffused may beprevented from leaking from the housing 210 at an interface between thehousing portions or pieces 210 a, 210 b. Upon depletion of the liquid211, the cartridge 200 may be readily removed and replaced with a likecartridge 200 for continued treatment of the environment surrounding thediffusion device, and the depleted cartridge 200 may be discarded as anintact unit or collected for refurbishment purposes.

With reference to FIG. 8, the housing 210 of the cartridge 200 mayinclude an upper housing portion 210 a and a lower housing portion 210 bfixedly coupled together. A cartridge inlet 212 may be provided at abottom end of the lower housing portion 210 b to receive a flow ofpressurized gas during operation and a cartridge outlet 214 may beprovided in the upper housing portion 210 a for discharging diffusedliquid generated by the cartridge 200 during operation. The cartridgeinlet 212 and the cartridge outlet 214 may be aligned along a centralaxis A₂ defined by the housing 210. The housing 210 may be rotationallysymmetric about the central axis A₂. For example, as shown in FIG. 8,the housing 210 may resemble a generally cylindrical vessel or similarreceptacle that is rotationally symmetric about the central axis A₂. Inother instances, the housing 210 may be asymmetrically shaped and thecartridge inlet 212 and cartridge outlet 214 may not be alignedvertically along a common axis. Respective caps or plugs (not shown) maybe provided to temporarily close the cartridge inlet 212 and cartridgeoutlet 214 during storage, transport or the like to prevent fouling orcontamination of the cartridge 200 or possible leakage of the liquid 211retained therein.

Internal components and structures of the cartridge 200 and relatedfunctionality will now be described with reference to FIG. 8. Accordingto the illustrated embodiment of the cartridge 200, the internalcomponents and structures provide, among other things, a flow paththrough the cartridge 200 from the cartridge inlet 212 to the cartridgeoutlet 214, as represented by the arrows labeled 230 a-230 h. Wheninstalled in a host diffusion device, the cartridge inlet 212 is coupleda source of pressurized gas 202 such that the gas may be periodicallyforced through the cartridge 200 as generally represented by the arrowslabeled 230 a-230 h to combine with the liquid 211 and to exit as agas-liquid mixture comprising particularly small liquid particlescarried by the gas, referred to generally herein as a diffused liquid.

As shown in FIG. 8, the pressurized gas enters the cartridge 200 throughthe cartridge inlet 212 at a bottom end of the housing 210 and thenflows through a diffusion head 240 provided within the housing 210,which includes a venturi device 242 for drawing the retained liquid 211into the moving gas stream, and a cartridge insert 270 before exitingthe cartridge 200 through the cartridge outlet 214. More particularly,the pressurized gas enters the cartridge 200 through the cartridge inlet212 at a bottom end of the housing 210, as represented by the arrowlabel 230 a, and then flows upwardly through a gas supply conduit 252defined by an interior surface 254 of a lower portion 244 of thediffusion head 240, as represented by the arrow labeled 230 b. The gasthen flows through the venturi device 242 drawing in liquid 211 from afluid reservoir surrounding the lower portion 244 of the diffusion head240 within the internal housing cavity 213 of the housing 210 to createa gas-liquid mixture comprising atomized liquid (also referred to hereinas diffused liquid) that is discharged into an expansion chamber 248provided by an upper portion 246 of the diffusion head 240, asrepresented by the arrow labeled 230 c. The diffused liquid is thendirected toward an impact structure or surface 282 located opposite theventuri device 242 wherein at least some of the diffused liquid impactsand collects on the impact structure or surface 282 and is routed backto any remaining fluid 211 in the fluid reservoir to be reintroducedinto the gas stream by the venturi device 242. At least some other ofthe diffused liquid is redirected to flow down around bulkhead portions256 of the diffusion head 240 and to pass through passageways 258 in thediffusion head 240 leading to a portion of the internal cavity 213 ofthe housing above the fluid level L₃ of liquid 211 in the cartridge 200,as represented by the arrows labeled 230 d and 230 e. From there, someof the diffused liquid may collect on the exposed interior surfaces ofthe housing 210 or other internal structures of the cartridge 200, orotherwise precipitate out of the gas and atomized liquid, and rejoin theliquid 211 in the fluid reservoir to be reintroduced into the gas streamby the venturi device 242. Some other of the diffused liquid may bepropelled into the cartridge insert 270 via an inlet 272 thereof, asrepresented by the arrow labeled 230 f. From the inlet 272 of the insert270, the diffused liquid proceeds along a tortuous passage 276 (seeFIGS. 9 and 10) through the cartridge insert 270, as represented by thearrows labeled 230 g, before passing through an outlet passageway 215 inthe housing 210 that leads to the cartridge outlet 214 to be dischargedfrom the cartridge 200, as represented by the arrow labeled 230 h. Inmaking this convoluted journey from the expansion chamber 248 to thecartridge outlet 214, the liquid particle size distribution of thediffused liquid is refined such that only particularly fine particlesare successfully discharged from the cartridge 200 with relativelylarger particles collecting on one or more surfaces of the internalstructures and components of the cartridge 200, or otherwiseprecipitating out of the gas, for rejoinder with remaining liquid 211 inthe liquid reservoir for reintroduction into the gas stream passingthrough the venturi device 242.

As shown in FIG. 8, the diffusion head 240 may include a unitarydiffusion head body 241 including an upstream or lower portion 244 and adownstream or upper portion 246. For example, in some instances thediffusion head 240 may be molded or otherwise formed as a unitary pieceof material, such as a suitable plastic or polymeric material. The lowerportion 244 of the diffusion head 240 may be sized and shaped to nestclosely with a corresponding portion of the housing 210, as shown inFIG. 8, or to otherwise interface with the housing 210, and may befixedly joined to the housing 210 via spin welding, ultrasonic weldingother joining processes to create a liquid-tight seal between thehousing 210 and the lower portion 244 of the diffusion head 240. In someinstances, such as the example embodiment of the diffusion head 240shown in FIG. 8, the lower portion 244 of the diffusion head body 241may include a flange 243 or other feature, such as a step, projection,tab, indent, or groove, that interfaces with the housing 210 to assistin fitment and joining of the components.

With continued reference to FIG. 8, the lower portion 244 of thediffusion head body 241 includes an interior surface 254 that definesthe gas supply conduit 252 that leads from the cartridge inlet 212 at abottom end of the cartridge 200 toward the venturi device 242. The gassupply conduit 252 may also be partially defined by a divider portion245 of the diffusion head body 241 which divides the upper portion 246of the diffusion head 240 from the lower portion 244. The dividerportion 245 separates and isolates the gas supply conduit 252 from theexpansion chamber 248 with the exception of a flow passage 247 throughthe venturi device 242 which provides the only fluid communicationbetween the gas supply conduit 252 and the expansion chamber 248.

With continued reference to FIG. 8, the liquid 211 to be diffused maysurround the lower portion 244 of the diffusion head 240 such that gasenters the cartridge 200 from a bottom 218 of the cartridge 200 andpasses through a region of the diffusion head 240 surrounded by theliquid 211 before reaching the venturi device 242. At the venturi device242, the gas is accelerated via the flow passage 247 and a lowerpressure zone is created which draws the liquid 211 to be diffusedthrough a suction tube 219 that provides fluid communication between theliquid reservoir that surrounds the lower portion 244 of the diffusionhead 240 and the venturi device 242. The initial volume of liquid 211supplied with the cartridge 200 preferably does not fill the entireinterior cavity 213 of the housing 210, but rather defines a fluid levelL₃ that is below the venturi device 242.

As shown in FIG. 8, the diffusion head 240 may include a tube receivingpassage 249 in the divider portion 245 of the diffusion head body 241 toreceive one end of the suction tube 219 and to position an outlet of thesuction tube 219 in fluid communication with the flow passage 247 of theventuri device 242 such that the liquid 211 may be drawn into the pathof the pressurized gas as it is accelerated via the flow passage 247 ofthe venturi device 242. The flow passage 247 of the venturi device 242may comprise a convergent entrance, a narrow throat, a side port forintroduction of the liquid, and a divergent outlet which are configuredto accelerate the flow of gas, draw in the liquid 211 through the sideport and discharge diffused liquid into the downstream expansion chamber248 provided by the upper portion 246 of the diffuser head 240. The sizeand shape of the flow passage 247 may be configured based oncharacteristics of the gas flow, the geometry of the gas supply conduit252 and the volume and velocity of gas required to effectively drawliquid 211 up the suction tube 219 and atomize liquid 211 in the venturidevice 242.

With continued reference to FIG. 8, the diffused liquid may bedischarged from the venturi device 242 with sufficient force to cause atleast some of the atomized liquid particles suspended in the gas,particularly the relatively larger particles, to impinge upon andcollect on the underside of the cartridge insert 270, which is providedopposite the venturi device 242 to serve as an impact structure,preferably a concave impact structure. More particularly, the insert 270may include a lower portion having an indentation or depression 280 thatincludes an impact surface 282 to be impinged upon by the diffusedliquid generated by the venturi device 242 during operation. In someinstances, the impact surface 282 may be concave and may diverge in adownward direction to direct liquid condensed or collected thereonradially outward and downward. In some embodiments, the impact surface282 may be a conical or frustoconical surface. Liquid collecting on theunderside of the insert 270 may drip or run down onto the dividerportion 245 of the diffusion head 240 and drain to the liquid reservoirvia the passageways 258 provided in the upper portion 246 of thediffusion head 240, which in some embodiments may provide the only fluidcommunication between the expansion chamber 248 and the internal cavity213 of the housing 210 external of the diffusion head 240.

With reference to FIGS. 8 through 10, the insert 270 is positioned aboveof the diffusion head 240 and includes a body 271, an inlet 272 providedin the body 271 to receive the diffused liquid generated within thecartridge 200 during operation of the liquid diffusion device, an outletzone 274 defined at least in part by the body 271 through which todischarge the diffused liquid toward the external environment, and atortuous passage 276 extending between the inlet 272 and the outlet zone274 to aid in further reducing an average liquid particle size of thediffused liquid as the diffused liquid moves through the tortuouspassage 276 during operation. The inlet 272 may be located at or near aperiphery 273 of the body 271, the outlet zone 274 may be located at acentral region 275 of the body 271, and the tortuous passage 276 mayspiral or otherwise extend in a convoluted manner between the inlet 272and the outlet zone 274. The tortuous passage 276 may be at leastpartially defined by a vertical sidewall 278 of the body 271. Thesidewall 278 may extend from the periphery 273 of the body 271 into ortowards the central region 275 of the body 271. A floor 279 of theinsert 270 may be inclined or sloped toward the inlet 272 to assist inrerouting liquid that has precipitated out of the gas/diffused liquidmixture or that has otherwise collected on surfaces of the insert 270 asthe mixture passes through the tortuous passage 276 during operationback to rejoin any remaining liquid 211 in the internal cavity 213surrounding the lower portion 244 of the diffusion head 240 to bereintroduced into the gas stream passing through the venturi device 242.

As shown in FIGS. 8 and 9, the tortuous passage 276 may be open in anupward direction and may be at least partially capped with acorresponding portion 217 of the housing 210 when the cartridge 200 isfully assembled to define an aerosol outlet at a remaining uncoveredportion at the outlet zone 274. The insert 270 may be sandwiched betweenthe cartridge housing 210 and the diffusion head 240 in the assembledcondition. In the assembled condition, the diffusion head 240 and theinsert 270 extend longitudinally between the lower housing portion 210 band the upper housing portion 210 a to define a central core of thecartridge 200 that fully traverses the housing 210 in a longitudinaldirection.

The body 271 of the insert 270 is preferably formed as a single, unitarypiece that includes the tortuous passage 276 and is coupled to orotherwise positioned adjacent the upper portion 246 of the diffusionhead 240 to cap the expansion chamber 248. For example, in someinstances the insert 270 may be molded or otherwise formed as a unitarypiece of material, such as a suitable plastic or polymeric material. Theupper portion 246 of the diffusion head 240 and the insert 270 may besized and shaped to nest together. For example, the upper portion 246 ofthe diffusion head 240 may include a recess or shelf to receive andsupport the insert 270. In other instances, the upper portion 246 of thediffusion head 240 and the insert 270 may abut each other along planarsurfaces. In some embodiments, the insert 270 may be fixedly joined tothe diffusion head 240 via spin welding, ultrasonic welding or otherjoining techniques. Still further, although the diffusion head 240 andthe insert 270 are described herein as two separate componentspositioned or joined together, it is appreciated that the structures andfeatures of these components may be formed as a single unitary piece viaan additive manufacturing process, for example. In other instances, thestructures and features of the diffusion head 240 and the insert 270 maybe provided by more than two pieces that are joined or otherwise coupledtogether. In the particularly advantageous embodiment illustrated inFIGS. 8 through 10, however, the removable cartridge 200 consists, orconsists essentially, of the cartridge housing 210, the diffusion head240, the cartridge insert 270, the liquid 211 to be diffused, and theconduit or tube 219 that extends from a side of the venturi device 242of the diffusion head 240 to a lower region of the internal housingcavity 213 to enable the liquid 211 contained therein to be drawn intothe path of the pressurized gas as it moves through the venturi device242 during operation.

According to the illustrated embodiment, the tortuous passage 276 ishelical and makes at least two full revolutions about the central axisA₂. It is appreciated, however, that the tortuous passage 276 may takeon a variety of different forms. For example, the tortuous passage 276may include a curvilinear path that at least partially encircles thecentral axis A₂ as it moves from the inlet 272 toward the outlet zone274. In other instances, the tortuous passage 276 may include a pathwith a plurality of straight segments angled relative to each other toprovide a number of turns. In still other instances, the tortuouspassage 276 may include a path that combines linear and non-linear pathsegments. The cross-sectional shape of the tortuous passage 276 may alsovary along the tortuous passage 276. For example, a cross-sectionalprofile of at least a portion of the tortuous passage 276 may narrow ina downstream direction, that is in a direction from the inlet 272 towardthe outlet zone 274. This narrowing of the tortuous passage 276 mayfurther assist in refining the composition of the diffused liquid toinclude only the finest of liquid particles.

Irrespective of particular configuration, the tortuous passage 276follows a non-linear path that, among other things, assists inpreventing liquid 211 from leaking from the cartridge 200 when thecartridge 200 is upended. For example, if the cartridge 200 istemporarily held upside down, the tortuous passage 276 will assist inslowing the progression of liquid 211 within the cartridge 200 towardthe outlet zone 274 and hence the outlet 214 of the cartridge 200. Inthis manner, the cartridge 200 can be subsequently righted without theloss of fluid. Moreover, in the event the cartridge 200 is upended andcomes to rest on its side, the cartridge 200 is configured such that thevolume of liquid 211 supplied with the cartridge 200 will not rise abovethe central axis A₂ of the cartridge 200. In this manner, the tortuouspassage 276 will prevent the liquid 211 from spilling out of the outlet214 as the liquid 211 will be unable to move through the entirety of thetortuous passage 276 as at least a portion of the tortuous passage 276will be located above the fluid level of the liquid 211.

With reference again to FIG. 8, it will be appreciated that the housing210 and internal components of the cartridge 200 define a plurality ofdistinct chambers downstream of the venturi device 242 through which thediffused liquid sequentially travels before being discharged from thecartridge 200 and ultimately into a surrounding environment. Moreparticularly, the upper portion 246 of the diffusion head 240 and alower portion of the insert 270 define a primary expansion chamber 248immediately above the venturi device 242, a secondary chamber isprovided external of the diffusion head 240 and the insert 270 withininternal cavity 213 of the housing 210 above the fluid level L₃ of theliquid 211 to be diffused, and a tertiary chamber is provided by thetortuous passage 276 of the insert 270. Passageways or apertures 258 inthe upper portion 246 of the diffusion head 240 provide fluidcommunication between the primary expansion chamber 248 and thesecondary chamber. The upper portion 246 of the diffusion head 240 alsodefines a bulkhead or bulkhead portions 256 that impede the diffusedliquid generated by the venturi device 242 from exiting the primaryexpansion chamber 248 other than through the plurality of passageways orapertures 258. The inlet 272 of the insert 270 provides fluidcommunication between the secondary chamber and the tertiary chamber(i.e., the tortuous passage 276). Although only one inlet 272 and onetortuous passage 276 is shown providing the sole passage for thediffused liquid to exit the cartridge 200, it is appreciated that aplurality of inlets 272 may be provide to enable diffused liquid toenter one or more tortuous passages leading to the outlet 214 of thecartridge 200. The distinct chambers described above (i.e., the primaryexpansion chamber, the secondary chamber and the tertiary chamber)collectively assist in refining the composition of the diffused liquidto include only the finest liquid particles as the diffused liquid movessequentially through the chambers during operation. For instance, by thetime the gas/diffused liquid mixture exits from cartridge 200, there hasbeen some residence time in each of the distinct chambers to permitundesirably large liquid particles or droplets to precipitate orotherwise separate from the mixture and be returned to the liquidreservoir within the internal cavity 213 of the housing 210 external thediffusion head 240 for later atomization and dispersion. In this manner,the removable cartridge 200 and components thereof may provide acartridge solution for a diffusion device which has an efficient formfactor that is particularly effective at treating spaces with diffusedliquid having extremely small liquid particles.

In the present disclosure, the outlet 114, 214 of the cartridge 100, 200and/or outlet of a host diffusion device have permitted atomized liquidgenerated within the cartridge 100, 200 to flow directly into a space tobe treated. However, the cartridge 100, 200 could alternatively directdiffused liquid into an air transport or distribution system instead.The air transport system might include ductwork or other avenues thatwould permit the diffused liquid to be dispersed into a remotely locatedspace or a plurality of remotely located spaces. Thus, cartridge 100,200 could be used to diffuse and disperse liquid throughout an entirebuilding, for example, through the existing HVAC conduits.

It is also anticipated that cartridge 100 might be adapted to mountdirectly to a fitting on a conduit or source of compressed gas withoutthe need for mounting within or as part of a host diffusion device. Sucha fitting might permit cartridge 100, 200 to be positioned to treat airwithin a single enclosed space or may be used to treat air flowingthrough an air transport system and treat a plurality of spaces.Alternatively, a plurality of like cartridges 100, 200 might be used totreat individual spaces but may be linked to the same gas source. Thesource of compressed gas could then be controlled centrally for all ofthe spaces treated without the need for or provision of local controlsfor each treated space. Or each space could have a valve for controllingthe flow of gas through the cartridge 100, 200 and thus the strength orintensity of the treatment within a particular space. Such local controlvalves could be then permit the same or similar cartridges 100, 200 tobe used in conjunction with a common gas source to treat a plurality ofdifferent sized or configured spaces.

It may also be noted that the various diffusion devices, removablecartridges 100, 200 and components disclosed herein may include someform of operational control, such as controls for varying the pressure,velocity or timing of operation of an onboard air compressor to providegas flow through the cartridge 100, 200. In addition to using suchcontrols to alter the amount of liquid diffused by the devices and thecorresponding degree of treatment of a space, the characteristics of theliquid to be diffused may also affect the amount of liquid diffused andthe degree of treatment. For example, more viscous liquids may diffusemore slowly. The density of the liquid may also affect the degree oftreatment provided. These characteristics of the cartridge 100, 200 mayalso be taken into account when setting controls regarding the functionand operation of the diffusion devices into which the cartridges 100,200 are received.

Moreover, the various embodiments described above can be combined toprovide further embodiments. All of the U.S. patents, U.S. patentapplication publications, U.S. patent applications, foreign patents,foreign patent applications and non-patent publications referred to inthis specification and/or listed in the Application Data Sheet areincorporated herein by reference, in their entirety. Aspects of theembodiments can be modified, if necessary to employ features,structures, functionality or concepts of the various patents,applications and publications to provide yet further embodiments.

These and other changes can be made to the embodiments in light of theabove-detailed description. In general, in the following claims, theterms used should not be construed to limit the claims to the specificembodiments disclosed in the specification and the claims, but should beconstrued to include all possible embodiments along with the full scopeof equivalents to which such claims are entitled. Accordingly, theclaims are not limited by the disclosure.

This application is a continuation of U.S. patent application Ser. No.14/835,438, filed Aug. 25, 2015, which is a continuation of U.S. patentapplication Ser. No. 14/612,066, filed Feb. 2, 2015, now U.S. Pat. No.9,248,461, which claims the benefit of U.S. Provisional Application No.61/982,504, filed Apr. 22, 2014. The entire contents of each of theforegoing applications are hereby incorporated by referenced herein.

The invention claimed is:
 1. A scent dispensing system, comprising: aliquid diffusion unit including a pressurized gas source and a controlsystem for controlling discharge of a diffused scent containing liquidfrom the scent dispensing system; and a cartridge removably received inthe liquid diffusion unit, the cartridge comprising: a cartridgereceptacle comprising a plurality of pieces fixedly coupled together todefine a tamperproof receptacle and having an internal cavity partiallyfilled with a scent containing liquid to be diffused; a venturi devicewithin the internal cavity of the cartridge receptacle for generatingthe diffused scent containing liquid from the scent containing liquidcontained in the internal cavity; and a gas supply conduit that extendsfrom a bottom end of the cartridge toward the venturi device through thescent containing liquid to be diffused to enable the venturi device tobe supplied with pressurized gas from the pressurized gas source of theliquid diffusion unit via the bottom end of the cartridge.
 2. The systemof claim 1, wherein the plurality of pieces join together in a manner toprevent non-destructive disassembly of the cartridge.
 3. The system ofclaim 1, wherein the venturi device is provided by a diffusion headlocated within the internal cavity of the cartridge receptacle.
 4. Thesystem of claim 1, wherein the cartridge includes an insert positionedabove of the venturi device, the insert including an inlet to receivediffused scent containing liquid generated by the venturi device, anoutlet zone from which to discharge some of the diffused scentcontaining liquid toward an external environment, and a tortuous passageextending between the inlet and the outlet zone.
 5. The system of claim4, wherein the tortuous passage of the insert is configured to aid inreducing an average particle size of the diffused scent containingliquid as the diffused scent containing liquid moves through thetortuous passage.
 6. The system of claim 4, wherein the tortuous passageis configured to provide a convoluted flow path that retards a flow ofthe scent containing liquid through the insert when the cartridge isupended.
 7. The system of claim 4, wherein the receptacle comprises of alower piece and an upper piece, and wherein the venturi device and theinsert are received between the lower piece and the upper piece with theinsert urged into contact with the upper piece.
 8. The system of claim4, wherein a primary expansion chamber is provided between the venturidevice and the insert.
 9. The system of claim 8, wherein a secondarychamber is provided within the internal cavity of the cartridgereceptacle and is in fluid communication with the primary expansionchamber via a plurality of apertures in a bulkhead structure.
 10. Thesystem of claim 1, wherein a plurality of chambers are provideddownstream of the venturi device through which the diffused scentcontaining liquid sequentially moves towards an outlet of the cartridge.11. The system of claim 10, wherein the plurality of chambers include aprimary expansion chamber, a secondary chamber and a tertiary chamber.12. The system of claim 11, wherein the primary expansion chamber islocated immediately above the venturi device, the secondary chamber isradially adjacent to the primary expansion chamber and surrounds theprimary expansion chamber, and the tertiary chamber is provided by aconvoluted passageway that extends from the secondary chamber toward theoutlet of the cartridge.
 13. The system of claim 11, wherein thesecondary chamber is provided above a fluid level of the scentcontaining liquid to be diffused and is separated from the primaryexpansion chamber by a bulkhead having a plurality of apertures thatprovide fluid communication between the primary expansion chamber andthe secondary chamber.
 14. The system of claim 1, wherein thepressurized gas source is an air compressor or a pump.
 15. The system ofclaim 1, wherein the control system includes controls that areconfigured to permit adjustment of the timing and/or the pressure levelof pressurized gas discharged from the pressurized gas source.
 16. Ascent dispensing system, comprising: a liquid diffusion unit including apressurized gas source and a control system for controlling discharge ofa diffused scent containing liquid from the scent dispensing system; anda cartridge removably received in the liquid diffusion unit, thecartridge comprising: a cartridge receptacle including a lower portionand an upper portion that are fixedly coupled together to preventnon-destructive disassembly of the cartridge, and having an internalcavity partially filled with a scent containing liquid to be diffused; aventuri device within the internal cavity of the cartridge receptaclefor generating the diffused scent containing liquid from the scentcontaining liquid contained therein; and a gas supply conduit thatextends from a bottom end of the cartridge toward the venturi devicethrough the scent containing liquid to be diffused to enable the venturidevice to be supplied with pressurized gas from the pressurized gassource of the liquid diffusion unit via the bottom end of the cartridge,wherein a plurality of chambers are provided downstream of the venturidevice through which the diffused scent containing liquid sequentiallymoves towards an outlet of the cartridge, the plurality of chambersincluding a primary expansion chamber, a secondary chamber and atertiary chamber, and wherein the primary expansion chamber is locatedimmediately above the venturi device, the secondary chamber is radiallyadjacent to the primary expansion chamber and surrounds the primaryexpansion chamber, and the tertiary chamber is provided by a convolutedpassageway that extends from the secondary chamber toward the outlet ofthe cartridge.